| The radiochemical methods proposed for evaluating heterotrophic activity in waters have been severely criticized in recent years because they are not considered to be sufficiently realistic. Thus, the possibility of directly measuring the heterotrophic consumption of naturally occurring Organic Carbon (OC) in fresh water samples incubated under controlled conditions has been evaluated. The analytical performances of two OC analyzers utilizable for this purpose are discussed here, and some examples of the results obtained by the direct measurement of OC consumption are presented. The consumption rates thus measured ranged from 11.6 to 50.2 mu gC/ 1.h. Although the technique discussed here is less sensitive than radiochemical methods, the few assumptions... |
